Thread by @hepatoMD

ALERT: Based on popular demand, #NAFLD #tweetorial for primary care starts here. I guess it's a risk of calling yourself the "hepatoMD".

Topics: What is #NAFLD? How to diagnose it? Who to worry about? Who to refer? How to monitor?

#medtwitter #FOAMed

#NAFLD is an umbrella term. On one end of the spectrum there is 'simple steatosis', and on the other end there is 'NASH'. NASH is the clinical entity liver folks worry about because it causes liver disease.

So what causes NAFLD?
Best way to think of it is as a metabolic disease caused by insulin resistance, that is caused by genetic/environmental/lifestyle factors leading to adiposity.

Obesity is a HUGE public health problem. Pun intended. The US is worse than Canada, but Canada is not much better off. Obesity-related health complications will continue to drive growth in health resource utilization in Canada.

The pathophysiology of fatty liver is complex. It's multi-faceted, there's no linear progression, and a host of individual factors that make predicting progression difficult. But with complexity lies therapeutic opportunity (more on that later).

So, at this point ask yourself - in my practice the % of patients with fatty liver are:

The population prevalence of fatty liver depends on the population and how you are looking for it!
-general population around 20-25%
-by ultrasound in a primary care practice 20-30%
-in a diabetes clinic 60%-100%

If you have NAFLD, your risk of a liver-related death goes from #13 overall to #3.
If you have NASH (inflammation and fat), your risk is higher but cardiac death is still the most common. However, lifetime risk of cirrhosis is at least 25%.

Clinically we do need to differentiate simple steatosis vs NASH.
-simple steatosis: aggressive lifestyle interventions, but no need for liver-specific intervention
-NASH: lifestyle and liver-specific interventions, closer monitoring especially for liver cancer
BUT HOW??

NASH is a pathologic diagnosis, and biopsy is the gold standard. But we can't do that on everyone. So, instead we look for fibrosis/scar (a feature of NASH but not of simple steatosis).

There are many ways to do look for fibrosis, and we desire a way that is non-invasive, accessible and cheap. In practice the simplest and likely most accurate way is to use the NAFLD score. They even have a website: nafldscore.com

If your NAFLD score excludes fibrosis, you are probably dealing with simple steatosis and can counsel the patient and follow along by repeating the NAFLD score every couple of years.
But, if your NAFLD score detects advanced fibrosis, that's probably someone with NASH.

There are other tools to use besides NAFLD score, but I won't cover them all. I am just one person!

Once you identify NASH, then there are 2 buckets of treatment to consider. Those for the metabolic syndrome features, and those for the liver.

There are many different treatments that have been studied. The BEST will always be weight loss, 7-10% target. And there is a lot of research ongoing right now, one day we may have actual drugs like FXR-agonists, and others.

A note on diets.
When the patient doesn't have a lot of fibrosis, the type of diet is unimportant as long as they achieve weight loss.
But as the severity of fibrosis increases, mediterranean-style diet outperforms others.

Oh BTW - did I mention there is A LOT of research going on.

But coming back to primary care, what is one to do?
First, identify NASH.
Second, refer NASH for detailed assessment and consideration of clinical trials.
Third, monitor simple steatosis with annual or bi-annual liver enzymes, and a fibrosis score like NAFLDscore.
Fourth, retweet

Here's what the specialist might do when they see the patient.

NAFLD is a subject are that is dramatically evolving every year. We are learning more about prevalence, contributing factors, tests to quantify fat/fibrosis, specific treatments, and the role of multi-disciplinary team approaches. One day, NAFLD care will look like DM care.

That ends my brief-ish tutorial. If you got this far, blame @DocMCohen for requesting it. I hope it was good enough to take away at least 1 point about fatty liver. Ask questions below, will do my best to answer them. Adieu!

My opinion of this tweetorial: